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New Results in Charmless B Meson Decays at

New Results in Charmless B Meson Decays at. Justin Albert Univ. of Victoria. Representing the BaBar Collaboration. 20 July, 2013. Overview: 2 (of Many ) New BaBar Results. Evidence for B 0 → ww , and improved limit for B 0 → wf .

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New Results in Charmless B Meson Decays at

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  1. NewResultsinCharmless BMesonDecaysat Justin Albert Univ. of Victoria Representing the BaBar Collaboration 20 July, 2013

  2. Overview:2 (of Many) New BaBar Results Evidence for B0→ ww, and improved limit forB0→ wf. Measurement ofCP violation in B decays to three charged kaons. Brand new! To be submitted to PRL arXiv:1201.5897, PRD 85:112010 (2012); Also arXiv:1305.4218, SLAC-PUB-15451 New Results in Charmless B Decays at 20 July 13 J. Albert2

  3. Evidence for B0→ ww, and improved limit forB0→ wf Brand new! To be submitted to PRL

  4. B0→ ww and B0→ wf: Motivation • Anomalies in charmless decays with loops: Naively expect here • Quitelow value of longitudinally-polarized fraction in φK*. • Potential signs ofnew physics in loops…? SM expected BFs: B0→ ww : O(1 x 10-6) B0→ wf : O(1 x 10-7) • (Somewhat) low values of CP asymmetries. New Results in Charmless B Decays at 20 July 13 J. Albert3

  5. 233 x 106BB decays B0→ ww and B0→ wf : Previous Measurement at (2006) B0→ ww Events / 2.5 MeV B0→ wf Events / 5 MeV 5.25 5.26 5.27 5.28 5.29 mES arXiv:hep-ex/0605017, PRD-RC 74, 051102 5.25 5.26 5.27 5.28 5.29 mES +1.3 • B()< 1.2 x 10-6(90% CL), B() =(1.8-0.9 ± 0.4) x 10-6 (< 4.0 x 10-6@ 90% CL) • 2s excess for B0→ ww in 2006 measurement, however both results were limits. • At leading order,  is pure penguin and  is a penguin-tree combination. • Limits on BFs can provide a constraint on amplitudes of K*. Neither helicity amplitude measurements, nor even significant signal peaks, are required. New Results in Charmless B Decays at 20 July 13 J. Albert4

  6. 471 x 106BB decays B0→ ww andB0→ wf: Reconstruction • Full reconstruction of B0 candidates, with w→ p+p-p0andf→ K+K-. • Resulting B0 signal candidates are characterized by the standard variables: • For a candidate to be selected, it must satisfy |DE| < 200 MeV and 5.24 < mES < 5.29 GeV, and have a vertex probability > 0. • Event shape variables are additionally used to help reject continuum background. mES = New Results in Charmless B Decays at 20 July 13 J. Albert5

  7. 471 x 106BB decays B0→ ww and B0→ wf : Maximum Likelihood Fit • We use an unbinned maximum likelihood in the 8 (ωϕ) or 9 (ωω) variables: • The likelihood is defined as: where Yjare the free parameters of the fit, i.e. the number of events for each hypothesis (signal, combinatoric background, and peaking background), and Pj(xi) are the probabilities for each hypothesis evaluated from the vector of 7 observables xi, for each of the N total events. • mES • DE • the resonance masses (2) • the resonance helicities (2) • an event shape Fisher discriminant • +the ω “internal” helicity angle(s) (i.e. angle of the π0in the dipion rest frame) = 2extra variables for ωω, but just1extra variable forωϕ: Di-pion (p+p-) rest frame: p0 q p+ p- w New Results in Charmless B Decays at 20 July 13 J. Albert6

  8. 471 x 106BB decays B0→ ww andB0→ wf: Fit Result PRELIMINARY PRELIMINARY Stat. errors only Stat. errors only With systematics With systematics +0.3 • B() =(1.2 ± 0.3-0.2 ) x 10-6(4.4ssignificance) • B()< 0.7 x 10-6(90% CL) • Largest systematic contributions from fit yield bias estimation (O(5 events) ≲ 10% for ww) and marginalizing over longitudinal vs transverse fraction (fL = 0.88 is used as the nominal central value). Brand new! To be submitted to PRL New Results in Charmless B Decays at 20 July 13 J. Albert7

  9. 471 x 106BB decays B0→ ww and B0→ wf: Projection Plots PRELIMINARY PRELIMINARY PRELIMINARY PRELIMINARY Brand new! To be submitted to PRL New Results in Charmless B Decays at 20 July 13 J. Albert8

  10. Measurement of CP violation in B decays to three charged kaons arXiv:1201.5897, PRD 85:112010 (2012)

  11. arXiv:1201.5897, PRD 85:112010 (2012) 471 x 106BB decays B → 3KCPV intermediate state New Results in Charmless B Decays at 20 July 13 J. Albert9

  12. arXiv:1201.5897, PRD 85:112010 (2012) 471 x 106BB decays B → 3KCPV: Dalitz We measure the isobar coefficients cj. B+→ K+KSKS B0→ K+K-KS B+→ K+K-K+ New Results in Charmless B Decays at 20 July 13 J. Albert10

  13. arXiv:1305.4218, SLAC-PUB-15451 B → 3KCPV: CPV(Dalitz) Babar vs. LHCb ACP results – similar patterns but constant offset (?): = = f(1020) = = New Results in Charmless B Decays at 20 July 13 J. Albert11

  14. B → 3KCPV: Summary arXiv:1201.5897, PRD 85:112010 (2012) ; arXiv:1305.4218 (2013), SLAC-PUB-15451 471 x 106BB decays • Tension in ACP measurements between Babar and LHCb; is there a nonzero offset? New Results in Charmless B Decays at 20 July 13 J. Albert12

  15. Summary Evidence (at 4.4slevel) for B0→ ww, and improved limit forB0→ wf. Measurement ofCP violation in B decays to three charged kaons. +0.3 Brand new! To be submitted to PRL B() =(1.2 ± 0.3-0.2 ) x 10-6 B()< 0.7 x 10-6(90% CL) arXiv:1201.5897, PRD 85:112010 (2012) ; arXiv:1305.4218 (2013), SLAC-PUB-15451 World’s most precise measurement of beff(fKS): (21 ± 6 ± 2) degrees New Results in Charmless B Decays at 20 July 13 J. Albert13

  16. Backup Slides

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